I can bench press 140 pounds, I'm quite a skinny fucker too, I've been working to get to this weight but my muscles just never get bigger. I have whiteman genetics so I don't think that's the problem.
Arm

Meaning cut out the excess things that aren't helping. 200 push ups is excessive if you want mass. I'm sure you've heard about not running excessive amount while trying to build strength. I'd imagine that whats happening, along with your infrequency in visiting the gym is any benefits are being undone by the lack of rest and/or nutrition.

Foods like beans and nuts are generally going to be fairly inexpensive, but are high in protein.